Viagra generally refers to sildenafil, which is best avoided by normal people. Sildenafil is mainly used to treat erectile dysfunction, and adverse reactions such as headache, flushing, dizziness, and visual abnormalities may occur when taking this medication, in addition to which it should be contraindicated in patients who are allergic to sildenafil or any of the other excipients in the product. Adverse reactions are similar in healthy volunteers taking low and high doses of sildenafil, but the incidence and severity increase with it. Therefore, it is better for normal people not to take Sildenafil in order to avoid serious consequences for the body. If normal people take sildenafil after the occurrence of uncomfortable symptoms, need to go to a regular hospital in time, under the guidance of the doctor for standardized treatment.